Drilling machine



May 12, 1931. B. 2. GOOD DRILLING MACHINE Filed Jan. 23,. 1950 PatentedMay 12, 1931 BRUCE Z. GOOD, OF 'IIFFIN, OHIO, ASSIGNOR THE LOOIJIISIVIACHIIJE COMPANY, OF TIFFIN, OHIO, A CORPORATION OE OHIO DRELLINGMACHINE Application filed January 23, 1830. Serial Ha li 32,941.

This invention relates to drilling machines, and particularly to themeans by which the drilling tool is raised and lowered.

In machines of the type to which the invention relates, the linecarrying the drilling tool passes about a sheave mounted on the end of aspudding beam which is rocked about a horizontal axis to raise and lowerthe tool. The movement of the spudding beam is controlled by a crank,rotating about a horizontal axis in front of the spudding beam axis andhaving a wrist pin which rides in a slot extending longitudinally of thebeam. In the construction heretofore used, however, the upward swing ofthe spudding beam as the tool starts on its downward stroke has been sofast that too much slack was provided in the line, permitting it to kinkor to become tangled. Also, as the tool rebounded after the impact, theline would not be withdrawn quickly enough to catch it on the rebound,thus causing a sudden jerk on the line as it became taut.

With the above facts in mind, it is the object of the present inventionto provide means for controlling the movement of the spudding beam sothat upon the downward stroke of the tool, the line will be released ata rate closely approximating the rate at which the tool drops under theinfluence of gravity. Such a result is efiected by a curved slot, theconvexity of the curve being downward. Such a slot also causes the lineto be withdrawn with a quick initial movement so that the tool is caughton the rebound and con tinues its upward movement without any jerk.

The invention in its preferred form is illustrated in the accompanyingdrawings, in which Figure 1 is a side elevation of the spudding beam andthe parts associated therewith.

Figure 2 is a partial front elevation of the same. 1

As illustrated in the drawings, the spudding beam 5 is pivoted at itsrear end, as indicated at 6, and a keeper 7 is secured to its front endfor receiving ayoke 8 or similar support, which carries a rope guide,here represented as a sheave 9. The drill line 10 passes about thesheave 9 and about a sheave 11, which is mounted on the pivot 6.

The beam 5 is oscillated aboutthe pivot 6 through the medium of a crank12 mounted on a shaft 13 which may be continuously rotated by a bullwheel l i secured thereon or by other suitable means. The beam 5 isenlargedon its underside adjacent the crank 12, as indicated at 15, andis covered by a shoe or plate 16 suitably secured thereto. An iron 17,preferably T-shaped in cross section is mounted on the underside of thebeam in any suitable manner. In the present instance the iron 17 isshown as having one end secured by bolts 18 and the other end mountedwithin the yoke 8, and held by a buffer spring 19. Thus a slot 20 isprovided with upwardly curved ends, which receives a wrist pin 21carried by the end of the crank 12. A suitable anti-friction roller orcollar 22 may be mounted on the pin 21.

In the operation of the machine, when the drill line has been withdrawnto raise the tool, the pin 21 will be approximately at the bottom of itscircular path. As the crank continues to rotate, assuming that itrotates in a clockwise direction as viewed in Figure 1, the pin 21,approximately during the first 90 of its rotation, will ridesubstantially from the center of the slot 21 to the rear end thereof. Ifthe slot 20 were straight, the rate of movement of the front end of thebeam 5 would be substantially proportional to the sine of the anglethrough which the crank had passed since leaving its lowermost position.In other words, the maximum rate of movement of the beam would bereached when the crank had rotated througl'i an angle of approximately90. By curving the rear end of the slot upwardly, however, theacceleration in the movement of the beam 5 is lessened and rendered moreuniform, so that it closely approximates the acceleration of themovement of the tool under the influence of gravity. As the pin entersthe upper half of its orbit, it moves from the rear end of the slot 20toward the center thereof and the curvature of the slot causescontinuous acceleration in the movement of the beam 5 until the pin 21approaches its uppermost position. The curve of the slot 20 is sodesigned that the upward movement'of the beam 5 for the greater part ofits duration approximates the rate at which the tool drops 5 under theinfluence of gravity so that there is always as little slack as possiblein the line 10.

As the pin 21 passes through the uppermost part of its path, the toolstrikes the bottom of the hole and rebounds. Aset-he pin 21 passestoward the front end of the slot the initial downward movement of beamis much quicker than it would be with a straight slot so that the lineis withdrawn quickly enough to catch the tool on the rebound and tocontinue the upward movement thereof with an approximately uniformdeeeIeration until the pin 21 and the beam 5 reach their lowermostposition.

Vhile I have shown and illustrated the invention in what appears to beits preferred form, it is to be understood that the same may be modifiedto a considerable extent without any material departure from 25 thescope of the invention as defined by the claim.

\Vhat I claim is: In a drilling machine, the combination of a spuddingbeam pivoted at its rear end,;a

guide mounted on the forward end of said beam, a flexible lineassociated with said guide, said beam having a slot extendinglongitudinally of its front end, and a-crankrotating about a horizontalaxis and having a pin riding in said slot to rock the beam and therebycontrol the tightening and the releasing-of said line, said slot beingcurved upwardly toward each end.

In testimony whereof I have hereunto 0 signed myname to thisspecification.

BRUCE 2. GOOD.

